Browse Articles

Co-creating micro-scale nature-based designs in Tshwane, South Africa: balancing stakeholder interests in the design process

Is the Whole the Sum of its Parts? Neural Computation of Consumer Bundle Valuation in Humans

Humans are often tasked with making decisions about bundles of multiple items and very little is known about how the human brain aggregates, computes, and represents value in such cases. We investigated how the brain evaluates consumer items, both individually and in bundles, and how this activity relates to choice behavior. Human participants ( N  = 14; 7 female, 7 male) completed a deep-functional MRI protocol while we elicited behavioral valuations for single and bundled items. Behaviorally, we find that bundle values are sub-additively discounted compared to the sum of individual item values. Neurally, we find that the same distributed network in prefrontal cortex computes the value of a bundle and its constituent individual items, but the value representation undergoes a normalization that actively rescales across bundle and single item contexts. These findings suggest that generalized value regions contextually adapt within a valuation hierarchy, as opposed to utilizing an absolute value code.

Cu-Catalyzed Enantioselective and Divergent Synthesis of 5–5-Membered Atropisomers via Direct Atroposelective C–C/C–N Axial Bond Formation

Insights into the operational stability of wide-bandgap perovskite and tandem solar cells under rapid thermal cycling

Abstract Temperature variations can induce phase transformations and strain in perovskite solar cells (PSCs), undermining their structural stability and device performance. Despite growing interest, the operational stability of triple-cation wide-bandgap (WBG) PSCs and tandem solar cells (TSCs) under rapid solar-thermal cycling remains poorly understood. Here, we investigate the operational stability of WBG PSCs (~1.68 eV) with a champion power conversion efficiency (PCE) of 24.31% and extend the study to TSCs. We find that degradation during device operation under rapid solar-thermal cycling (temperature change rate of 10 °C/min) is independent of passivation and occurs in two distinct regimes: an initial burn-in phase, which accounts for a rapid 60% relative loss in performance, followed by a steady degradation characterized by temperature-dependent fluctuations in photovoltaic parameters. By operando grazing-incidence wide-angle X-ray scattering and photoluminescence measurements, we reveal that temperature-induced strain, phase transition, and the increased non-radiative recombination collectively contribute to the degradation of PSCs. This work advances the understanding of the degradation mechanisms of WBG PSCs and TSCs, providing insights toward improving their operational thermal stability for real-world applications.

Parametric study and fuel quality assessment of biofuel from hydrothermal liquefaction of microalgae grown in municipal wastewater

Abstract Hydrothermal liquefaction (HTL) of algal biomass is a promising approach for renewable biofuel production. The actual study investigates the effects of reaction temperature (225–325 °C), residence time (15–60 min), algae-to-water mass ratio (1:5–1:20), and pressure on the yield and quality of biofuel derived from municipal wastewater-grown mixed algal-cyanobacterial biomass. Eleven HTL experiments were conducted, and the resulting products were separated into gas, liquid, and solid phases for thermal and chemical analyses. Selected biofuel samples were characterized using gas chromatography–mass spectrometry (GC–MS), elemental analysis, and thermogravimetric analysis (TGA). The biofuels contained complex mixtures of aliphatic hydrocarbons, aromatics, phenolics, carboxylic acids, esters, and nitrogen-containing compounds, classified into biogasoline, bio-jet fuel, biodiesel, and motor oil fractions. Optimal yields of biofuel, gas, and solid residues were 16.86%, 26.14%, and 40.43%, respectively, achieved at a 1:10 algae-to-water ratio, 30 min reaction time, and 250 °C. The biofuel composition comprised 11.37% gasoline, 29.41% kerosene, 9.71% diesel, with a heating value of 42.93 MJ·kg⁻¹. A higher fraction of gasoline, kerosene and diesel-range compounds enhances energy density and combustion stability, while lower oxygen and nitrogen content improves storage and fuel properties. Solid residues exhibited uniform physical properties but were unsuitable for high-grade biochar due to low carbon and high inorganic content. These findings demonstrate that HTL of municipal wastewater-grown microalgae is a viable route for sustainable biofuel production, integrating resource recovery with renewable energy generation, while systematically evaluating key operational parameters and characterizing the resulting biofuel for downstream applications.

Correction to “A Data Science-Guided Approach for the Development of Nickel-Catalyzed Homo-Diels–Alder Reactions”

Identification of antimicrobial peptides from ancient gut microbiomes

Abstract Fecal coprolites preserve ancient microbiomes and are a potential source of extinct but highly efficacious antimicrobial peptides (AMPs). Here, we develop AMPLiT (AMP Lightweight Identification Tool), an efficient tool deployable to portable hardware for AMP screening in metagenomic datasets. AMPLiT demonstrates AUPRC performances of 0.9486 ± 0.0003 and reasonable overall training time of 3200 ± 53 s. By computationally utilizing AMPLiT, we analyze seven ancient human coprolite metagenomes, identifying 160 AMP candidates. Of 40 representative peptides synthesized, 36 (90%) peptides demonstrate measurable antimicrobial activity at 100 μM or less in vitro. Strikingly, approximately two-thirds of these peptides are sourced from Segatella copri , a dominant ancient gut commensal that is conspicuously underrepresented in modern populations, particularly those with Westernized lifestyles. Representative S. copri -derived AMPs exhibit disruptions against membranes of pathogenic bacteria, coupled with low cytotoxicity and hemolytic risk. In vivo, lead peptides demonstrate potent antibacterial and wound-healing efficacy comparable to traditional antibiotics, especially in combating gram-positive pathogens. Our findings highlight the ancient gut microbiomes as sources of novel AMPs, offering valuable insights into the historical role of S. copri in human health and its decline in contemporary populations.

Dipolar modulation of surface states in GaN via molecular ionization energy

MnSi ₂ Te ₄ : A van der Waals Antiferromagnetic Semiconductor with Large Negative Magnetoresistance

Multi-center multi-omics integration predicts individualized prognosis in medullary thyroid carcinoma

Knowledge and prevention practices regarding cytomegalovirus among pregnant women in Gondar city a multicenter cross-sectional study

Merging Enzymatic Catalysis with Iron Catalysis for Highly Stereoselective Heparan Sulfate Oligosaccharide Assembly

Symmetry in category systems across languages

Abstract Language reflects how people organize experience into categories, and cross-linguistic comparison can help to identify general principles that shape categorization. Here we argue that symmetry is one such principle, and present a symmetry-based theory that predicts whether category systems for a given domain tend to include an even or an odd number of categories. We test the theory against cross-linguistic data previously compiled for a range of domains and find that deictic day-naming and tense-marking systems tend to have an odd number of categories, but that systems for domains including seasons, phases of the moon, kinship, and cardinal directions tend to have an even number of categories. Our results therefore provide evidence of the widespread influence of symmetry on categorization across languages and domains.

Underwater image enhancement using colour balancing and morphological residual processing through gamma correction

Abstract Underwater images typically suffer from poor visibility, low contrast, and severe color distortion caused by wavelength-dependent absorption and scattering of light. These degradations not only reduce visual quality but also affect subsequent analysis and interpretation in marine and robotic imaging applications. To address these challenges, this study presents an efficient underwater image enhancement (UIE) framework that integrates color balancing, morphological residual processing, and gamma correction to achieve natural color restoration and structural enhancement. Initially, an adaptive color compensation strategy corrects the imbalance in red and blue channels, followed by morphological residual processing that refines fine textures while suppressing unwanted noise. The enhanced outputs are then fused through an adaptive multiscale fusion process guided by optimized weight maps to preserve both global illumination and local detail. A final gamma correction step ensures perceptually balanced contrast and brightness. The proposed method requires no training data or prior depth estimation making it computationally efficient and robust for real-time applications. Extensive experiments conducted on multiple benchmark underwater datasets demonstrate that the proposed approach consistently outperforms 22 state-of-the-art UIE techniques in both qualitative and quantitative assessments. The method achieves superior results in terms of peak signal-to-noise ratio (PSNR), structural similarity index measure (SSIM), underwater image quality measure (UIQM), and underwater color image quality evaluation (UCIQE) metrics, confirming its capability to restore realistic colors, enhance visibility, and preserve fine details. The proposed framework provides an effective and lightweight solution for practical underwater imaging enhancement. This work supports SDG 14 (Life Below Water) by enhancing underwater imagery for marine monitoring, SDG 9 (Industry, Innovation and Infrastructure) through an efficient real-time imaging framework, and SDG 12 (Responsible Consumption and Production) by enabling accurate underwater inspection that promotes sustainable resource use.

The Power of Catalytic Centers and Ascorbate in Boosting the Photocatalytic Hydrogen Evolution Performance of TpDTz 2D-COF

Sediment transport by Greenland’s icebergs

Abstract Ice-rafted debris (IRD) from Greenland’s tidewater glaciers provides key inputs to biogeochemical cycles, sequesters sediment in fjords, and leaves evidence of paleoclimate conditions. Previous work has shown that most IRD is entrained in basal ice, but studies have yet to translate this process knowledge into predictions of IRD export. Here, we combine field data and numerical models to quantify sediment transport in basal ice and estimate IRD fluxes. We present 210 samples of debris-rich icebergs, collected from three fjord systems, showing a long-tailed distribution of sediment concentrations between 0.1% and 45% by mass (3.48% median). Then, we develop a numerical process model of erosion and entrainment to predict the thickness of debris-rich ice layers and the IRD flux from each outlet. Across our selected fjords, we show a first-order relationship between a catchment’s ice yield and sediment yield. By extrapolating this relationship across Greenland’s marine-terminating outlets, we estimate that icebergs export 454 Mt a −1 of IRD (with a 95% confidence interval from 292 to 716 Mt a −1 ), representing up to one-third of Greenland’s total sediment transport. Our results demonstrate the significant role of icebergs in Greenland’s sediment budget, improving our understanding of how sediment export from glaciers and ice sheets will change under a warming climate.

Longitudinal changes in neurometabolites in pediatric migraine across child development: a pilot study

Chemoenzymatic Synthesis of Structurally Diverse Terpenoids from Farnesyl Pyrophosphates Modified at the Central Alkene Unit

Comprehensive mapping of RNA modification dynamics and crosstalk via deep learning and nanopore direct RNA-sequencing

Smelling the romantic partner’s natural body odor increases psychological and autonomic but not cortisol stress responses

Abstract While social support from romantic partners is known to ameliorate stress responses, it remains unclear whether perceiving a partner’s body odor can elicit similar stress-buffering effects. In this study, 179 participants living in heterosexual romantic relationships underwent either the Trier Social Stress Test (TSST) or a non-stressful control condition while being exposed to their partner’s body odor (collected under standardized conditions over five consecutive nights) or a neutral, non-social control odor presented via an olfactometer. The partner’s odor had no effect on cortisol release. However, contrary to previous findings, subconsciously smelling one’s own partner increased subjective stress and heart rates. Potential underlying mechanisms include the causal misattribution of attraction-related, arousal-induced heart rate increases to the stressful experimental situation, or an evolutionarily adaptive mechanism that amplifies stress responses when a loved one is potentially involved in the threatening situation.